On its December 31, 2019 balance sheet, Clark Company appropriately reported a $10,000 debit balance in its Fair Value Adjustment (available-for-sale) account. There was no change during 2020 in the composition of Clark's portfolio of debt investments held as available-for-sale securities. The following information pertains to that portfolio Security Cost Fair value at 12/31/2020 $125,000 $160,000 100,000 85,000 175,000 125.000 $400,000 $370.000 X Y Z What is the balance of the AOC account due to debt investments in Stockholder's Equity at 12/31/2020? Select one O a $30,000 debit b. 510,000 debit O $40,000 debit d. 50 e. $30,000 credit 1 $10,000 credit 9 $40,000 credit